Members of the phylum nematoda [round worms] have been in existence for an estimated one billion years. This makes them one of the most ancient and diverse types of animals now available for study on the earth. These organisms are thought to have evolved from simple animals. Two nematode classes—the Chromadorida and Enoplea diverged so long ago that it is difficult to know the exact age of the two lineages of the phylum.
Nematodes are multi-cellular organisms in the group Ecdysozoa. These are organisms that can shed their cuticle. Also included in this group with nematodes are insects, arachnids and crustaceans. Most literature suggests that based upon molecular phylogenic analysis, it would appear that nematodes have evolved their ability to parasitize animals and plants several times during their evolution. What appears clear is that nematodes have evolved to fill almost every conceivable niche on earth that contains some amount of water. Most nematodes are free-living, and feed on bacteria, fungi, protozoans and other nematodes, and many others are parasites for animals or plants.
The U.S. Department of Agriculture and other agencies have long known and reported that plant parasitic nematodes are recognized as one of the greatest threats to crops throughout the world. In fact, nematodes, alone, or in combination with other soil microorganisms have been found to attack almost every part of the plant, including roots, stems, leaves, fruits and seeds. In one recent report, a survey of more than 35 states regarding various crops indicated that nematode-derived losses reached upwardly to nearly 25%. Nematologists, who are studying the effects of nematodes, put this percentage considerably higher. In fact, one investigator reported that the difficulty with assessing nematode impact is that the damage resulting from a nematode infestation is often less obvious than that caused by other pests or diseases. In fact, losses that result from nematodes may not necessarily be a consequence of direct cell death, but may derive from other, more insidious aspects, such as interference with the root system, and reducing their efficiency in terms of access and uptake of nutrients, and water, and other similar effects. One commentator noted that nematodes are often described as the unseen enemy in crop production, and may be responsible for an estimated 100 billion dollars in global crop losses per year. Those skilled in the art have recognized that once a nematode population gets established, they have been nearly impossible to eradicate. Typically such infestations have been managed by crop rotation, introducing genetic crop resistance, and the use of chemicals and biologicals. With increasingly larger world populations projected by 2050, and later, an increase in food demand, in the order of 75%, is anticipated. Significant improvements, therefore, are necessary in terms of resource use efficiency, and crop yields, if these food demands are going to be met. However, this cannot be achieved if nematode infestations continue at their current levels.
The problems associated with nematode infestations, and the damage to crop yields are well known, and various devices, and methodology have been developed, through the years, in an attempt to manage these pests so as to increase the quality and amount of crops which are harvested. The literature has reported that fumigants, sometimes in conjunction with other chemical mitigants, have been the traditional means for controlling nematodes, heretofore. Currently, fumigant application is the dominant means for controlling nematodes in the United States, France, Japan, Italy and Spain. Fumigant sales account for 45% of the total nematocides sales globally. However, the high cost of the available fumigants has restricted their use to high value crops in countries where these admittedly toxic products can be applied safely and effectively. Many countries have severely restricted the use of fumigants, or completely banned them altogether. The consequence for farmers in these jurisdictions where fumigants have been restricted has been that they have very limited choices of products to control nematodes effectively, and consequently crop yields are lower. One of the most effective fumigants for nematodes is Methyl Bromide. Many farmers have recognized this soil fumigant is just short of a miracle for the management of this pest. Methyl Bromide has been shown, in a single treatment before planting, to control nematodes, other plant diseases, and weeds. However, Methyl Bromide is also recognized as a health and environmental hazard, and is being phased out under an international ban. Other fumigants are under testing by the U.S. Department of Agriculture, and other agencies. However, the recent literature does not show any of these fumigants have reached the level of efficacy that Methyl Bromide has. Investigators attempting to control soil pests, such as nematodes and the like, have sought other methods beyond that of fumigation and which is the common methodology used at this time. In view of this situation, a long felt need for other commercially viable, and environmentally friendly treatments for the management of a soil pest, like Nematodes, has been sought by assorted agricultural produce producers.
The Office's attention is directed to U.S. Pat. No. 1,737,866, which appears to be one of the earliest known patents, and which describes a method and apparatus for the practice of agriculture. This patent discloses the use of a plow device, and wherein the plow includes harrow discs or other oppositely charged implements, which act as electrodes, and wherein a source of electricity is passed into the plow-shares or harrow discs. The electrically energized harrow discs are reported, in this reference, to be effective in destroying germinating seeds, and inhibit the activity of insects, worms, larvae and eggs that are in the soil, thus practically exterminating them. The Office's attention is also directed to U.S. Pat. No. 2,750,712, to Rainey, and which relates to another apparatus and methodology for applying electrical current to a soil treatment area, and which is intended to destroy undesired weeds, grass and insect life by the application of electrical current to the insects, and undesired plants during cultivation. Still another attempt to apply electrical current to a cultivated area is seen in U.S. Plant Application Publication No. 2003/0150156 A1 to Flagler, et al. Again, this particular reference discloses a method and apparatus for eradicating nematodes, and other soil borne organisms, to a depth of up to several feet. This published U.S. patent application discloses the use of specially-shaped, electrically conductive metal shanks that are pulled through the soil profile by a tractor, or other suitable vehicle. Examples, of other prior art references which disclose the application of electrical current to a soil treatment area for the control of weeds, insects, nematodes, and the like, are also seen in U.S. Pat. Nos. 2,429,412; 2,588,561; 4,758,318; and 6,237,278 to name but a few.
While numerous attempts have been made to identify a means for controlling nematode infestations through the use of assorted means, including electrical charges passed through the soil, these attempts have not been successful or widely adopted by farmers and growers for a number of different reasons, including, but not limited to, the cost associated with utilizing the methodology or devices; the slow speed with which an area of soil can be effectively treated; and the resulting low efficacy of such treatments, in relative comparison to commercially available fumigants which have been used heretofore, such as Methyl Bromide. Notwithstanding the persistent problem of decreasing crop yields, and further in view of the international ban on fumigants such as Methyl Bromide, these previous prior art attempts at managing soil pests using electrical current have largely been ignored, or have been considered not particularly effective or commercially attractive to the degree necessary to meet the nematode threat now facing growers. While much research has been conducted regarding alternative means to control soil pests without the use of fumigants, and which have demonstrated, environmental and other health hazards, a long felt need has persisted that an alternative to fumigation must be identified if food growers are going to have any likelihood of increasing crop yields to meet the world food needs of an increasing population in the not too distant future, while avoiding collateral environmental damage.
A method and apparatus for the management of a soil pest is the subject matter of the present application.